Compilare: user.cpp: In member function ‘int Node::children_count()’: user.cpp:50:33: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < cs.size(); i++) ^ user.cpp: In member function ‘void Trie::insert(const string&)’: user.cpp:68:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i < w.size(); i++) { ^ user.cpp: In member function ‘std::string Trie::lcp(const string&)’: user.cpp:86:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i < w.size(); i++) { ^ user.cpp: In member function ‘int Trie::count(const string&)’: user.cpp:100:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (; i < w.size(); i++) { ^ user.cpp: In member function ‘Node* Trie::del_rec(const string&, Node*, int)’: user.cpp:113:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (pos == w.size()) { ^